There is a commercial benefit to providing many beverages, and in many cases foods, which have desirable sensory characteristics, such as flavour, mouthfeel, texture, smoothness/creaminess, and overall indulgency.
Often this is achieved by ensuring a high amount of fat content is present in the beverage, which generally provides all of these characteristics. A good example of this are thick-shakes as produced by fast-food outlets such as Wendy's™, McDonalds™ and so forth, which will have thick-shakes with a fat content significantly higher than say standard market milk (3.3% fat), sometimes in the order of up to 9% or more. The products are certainly desirable from an indulgency perspective.
Yet given the high fat and high calorie content in these beverages, they can be disadvantageous from a health perspective, as both a high calorie and high cholesterol diet are associated with a range of health issues such as obesity and heart disease. There is a definite need and desire from the public for beverages that retain these desirable sensory characteristics, yet are also healthier.
An important characteristic of thick-shakes is bubbles/froth, which is created by adding ice-cream. This froth has a positive impact on mouthfeel. However the addition of ice-cream not only increases the concentration of fat but also has other negative impacts—firstly, it's not available everywhere and secondly it contains various non-dairy ingredients such as emulsifiers.
An alternative to thick-shakes are milkshakes which lack ice-cream and subsequently have a lower fat content. However a disadvantage of milkshakes is a loss of sensory characteristics, particularly the indulgent mouthfeel provided by a high fat beverage.
In attempt to address these problems, various products and/or methods have been developed.
For example, NZ 563869 is directed towards using hydrophobin proteins and a surfactant to better retain gas bubbles within food products to improve the texture.
NZ 587796 is directed towards using alternan (polysaccharides made up of glucose units) as a thickening agent for various foodstuffs or beverages. Even within this document, there is reference to many thickening agents such as starch, gums, and so forth that are well known as conventional thickening agents to improve overall mouthfeel of a product without resorting to, in some cases, increased fat content.
NZ 552132 discloses an acidic milk drink that has a low fat, low calorie acidic milk drink yet with achieving a good flavour and light texture. It relies on inclusion of polydextrose and sugar.
In another example, US 2007/0065555 discloses a stabilised dairy foam which includes milk, a surfactant, a polysaccharide and a polymer.
In NZ 564378, methods of preparing frothy milk based beverages such as cappuccinos are described, including conventional techniques such as applying pressure and heat to produce bubble formation.
In other examples such as US 2011/0244076, CN 101156629B and WO 1996/033618, carbonation techniques are described in milk-based beverages for a number of reasons. However, these processes require pressurized gas (typically CO2 or N) which has a number of disadvantages.
First, carbonation requires specialized techniques and equipment, such that the beverage cannot be made conveniently like using mechanical aeration techniques. Second, in the context of milk based products, the fizzy texture from carbonation is not what many users are used to nor desire—such that carbonation is more often not only applied to non-dairy based soft drinks. Third, and again in the context of milk based products, the pH of the milk-based product decreases once carbonated, and this can lead to undesired stability issues with beverages such as coffee, which already lowers the pH somewhat.
These documents exemplify the need and the lengths to which the industry has gone to develop substitutes which provide good sensory characteristics without resorting to high fat products.
However, the main disadvantages of such products include:                Resorting to exogenous components such as gum or hydro-colloidal components (i.e. exogenous non-dairy components) to achieve the sensory characteristics, and/or improved volume retention. This is undesirable from a public perspective. The public prefers to have a product with a minimal amount (or none) of exogenous additives.        Some of the added components may lead to a displeasing flavour or texture, despite improving the viscosity and/or bubble retention.        The components may inconveniently lead to added manufacturing costs, complicated processing, or difficulty in its use.        Despite aiming to achieve good bubble formation in cases such as US 2007/0065555 or NZ 564378, the persistency of the bubbles may be poor, meaning that the end user may only have a short period to consume their beverage before the mouthfeel subsides.        In cases such as NZ 564378, the methodology and products may be overly complicated, inconsistent, and/or only be applicable to hot drinks. It would be beneficial to have a product that is easy to prepare and is applicable towards cold and hot beverages.        
It is an objective of the present invention to address the foregoing problems or at least to provide the public with a useful choice.
All references, including any patents or patent applications cited in this specification are hereby incorporated by reference. No admission is made that any reference constitutes prior art. The discussion of the references states what their authors assert, and the applicants reserve the right to challenge the accuracy and pertinency of the cited documents. It will be clearly understood that, although a number of prior art publications are referred to herein, this reference does not constitute an admission that any of these documents form part of the common general knowledge in the art, in New Zealand or in any other country.
Throughout this specification, the word “comprise”, or variations thereof such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
Further aspects and advantages of the present invention will become apparent from the following description which is given by way of example only.